'use strict';
 
function get_union(collection_a, collection_b) {
  let collection=collection_a;
  for(let i=0;i<collection_b.length;i++)
    {
        let sum=0;
      for (let j=0;j<collection_a.length;j++)
        {
          if(collection_b[i]==collection_a[j])
            {
              sum+=1;
            }
        }
      if(sum==0)
        {
            collection.push(collection_b[i]);
        }
    }
    return collection;
}

module.exports = get_union;

